﻿using FastExpressionCompiler;
using Microsoft.EntityFrameworkCore;
using System.ComponentModel.DataAnnotations;
using System.Linq.Expressions;
using System.Reflection;
namespace Masuit.Tools.Core.AspNetCore
{
    public static class DbSetExtensions
    {
        /// <summary>
        /// 添加或更新
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <typeparam name="TKey">按哪个字段更新</typeparam>
        /// <param name="dbSet"></param>
        /// <param name="keySelector">按哪个字段更新</param>
        /// <param name="entities"></param>
        public static void AddOrUpdate<T, TKey>(this DbSet<T> dbSet, Expression<Func<T, TKey>> keySelector, params T[] entities) where T : class
        {
            AddOrUpdate(dbSet, keySelector, entities.AsEnumerable());
        }

        /// <summary>
        /// 添加或更新
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <typeparam name="TKey">按哪个字段更新</typeparam>
        /// <param name="dbSet"></param>
        /// <param name="keySelector">按哪个字段更新</param>
        /// <param name="entities"></param>
        public static void AddOrUpdate<T, TKey>(this DbSet<T> dbSet, Expression<Func<T, TKey>> keySelector, IEnumerable<T> entities) where T : class
        {
            if (keySelector == null)
            {
                throw new ArgumentNullException(nameof(keySelector));
            }

            if (entities == null)
            {
                throw new ArgumentNullException(nameof(entities));
            }

            if (entities is not ICollection<T> collection)
            {
                collection = entities.ToList();
            }

            var func = keySelector.CompileFast();
            var keyObjects = collection.Select(s => func(s)).ToList();
            var parameter = keySelector.Parameters[0];
            var array = Expression.Constant(keyObjects);
            var call = Expression.Call(array, typeof(List<TKey>).GetMethod(nameof(List<TKey>.Contains)), keySelector.Body);
            var lambda = Expression.Lambda<Func<T, bool>>(call, parameter);
            var items = dbSet.Where(lambda).ToDictionary(t => func(t));
            foreach (var entity in collection)
            {
                var key = func(entity);
                if (items.ContainsKey(key))
                {
                    // 获取主键字段
                    var dataType = typeof(T);
                    var keyIgnoreFields = dataType.GetProperties().Where(p => p.GetCustomAttribute<KeyAttribute>() != null || p.GetCustomAttribute<UpdateIgnoreAttribute>() != null).ToList();
                    if (!keyIgnoreFields.Any())
                    {
                        string idName = dataType.Name + "Id";
                        keyIgnoreFields = dataType.GetProperties().Where(p => p.Name.Equals("Id", StringComparison.OrdinalIgnoreCase) || p.Name.Equals(idName, StringComparison.OrdinalIgnoreCase)).ToList();
                    }

                    // 更新所有非主键属性
                    foreach (var p in typeof(T).GetProperties().Where(p => p.GetSetMethod() != null && p.GetGetMethod() != null))
                    {
                        // 忽略主键和被忽略的字段
                        if (keyIgnoreFields.Any(x => x.Name == p.Name))
                        {
                            continue;
                        }

                        var existingValue = p.GetValue(items[key]);
                        if (p.GetValue(items[key]) != existingValue)
                        {
                            p.SetValue(items[key], existingValue);
                        }
                    }

                    foreach (var idField in keyIgnoreFields.Where(p => p.SetMethod != null && p.GetMethod != null))
                    {
                        var existingValue = idField.GetValue(items[key]);
                        if (idField.GetValue(items[key]) != existingValue)
                        {
                            idField.SetValue(items[key], existingValue);
                        }
                    }
                }
                else
                {
                    dbSet.Add(entity);
                }
            }
        }

        /// <summary>
        /// 添加或更新
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <typeparam name="TKey">按哪个字段更新</typeparam>
        /// <param name="dbSet"></param>
        /// <param name="keySelector">按哪个字段更新</param>
        /// <param name="entity"></param>
        public static void AddOrUpdate<T, TKey>(this DbSet<T> dbSet, Expression<Func<T, TKey>> keySelector, T entity) where T : class
        {
            if (keySelector == null)
            {
                throw new ArgumentNullException(nameof(keySelector));
            }

            if (entity == null)
            {
                throw new ArgumentNullException(nameof(entity));
            }

            var keyObject = keySelector.CompileFast()(entity);
            var parameter = keySelector.Parameters[0];
            var lambda = Expression.Lambda<Func<T, bool>>(Expression.Equal(ReplaceParameter(keySelector.Body, parameter), Expression.Constant(keyObject)), parameter);
            var item = dbSet.FirstOrDefault(lambda);
            if (item == null)
            {
                dbSet.Add(entity);
            }
            else
            {
                // 获取主键字段
                var dataType = typeof(T);
                var keyIgnoreFields = dataType.GetProperties().Where(p => p.GetCustomAttribute<KeyAttribute>() != null || p.GetCustomAttribute<UpdateIgnoreAttribute>() != null).ToList();
                if (!keyIgnoreFields.Any())
                {
                    string idName = dataType.Name + "Id";
                    keyIgnoreFields = dataType.GetProperties().Where(p => p.Name.Equals("Id", StringComparison.OrdinalIgnoreCase) || p.Name.Equals(idName, StringComparison.OrdinalIgnoreCase)).ToList();
                }

                // 更新所有非主键属性
                foreach (var p in typeof(T).GetProperties().Where(p => p.GetSetMethod() != null && p.GetGetMethod() != null))
                {
                    // 忽略主键和被忽略的字段
                    if (keyIgnoreFields.Any(x => x.Name == p.Name))
                    {
                        continue;
                    }

                    var existingValue = p.GetValue(entity);
                    if (p.GetValue(item) != existingValue)
                    {
                        p.SetValue(item, existingValue);
                    }
                }

                foreach (var idField in keyIgnoreFields.Where(p => p.SetMethod != null && p.GetMethod != null))
                {
                    var existingValue = idField.GetValue(item);
                    if (idField.GetValue(entity) != existingValue)
                    {
                        idField.SetValue(entity, existingValue);
                    }
                }
            }
        }

        private static Expression ReplaceParameter(Expression oldExpression, ParameterExpression newParameter)
        {
            return oldExpression.NodeType switch
            {
                ExpressionType.MemberAccess => Expression.MakeMemberAccess(newParameter, ((MemberExpression)oldExpression).Member),
                ExpressionType.New => Expression.New(((NewExpression)oldExpression).Constructor, ((NewExpression)oldExpression).Arguments.Select(a => ReplaceParameter(a, newParameter)).ToArray()),
                _ => throw new NotSupportedException("不支持的表达式类型：" + oldExpression.NodeType)
            };
        }

#if NET6_0_OR_GREATER

        /// <summary>
        /// 随机排序
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="query"></param>
        /// <returns></returns>
        public static IOrderedQueryable<T> OrderByRandom<T>(this IQueryable<T> query)
        {
            return query.OrderBy(_ => EF.Functions.Random());
        }
#endif
    }
}
